The usual automotive ignition cable includes a central core of glass filaments, bonded together with a conductive material (e.g., an acrylic latex or silicone dispersion) and surrounded by one or more layers of coaxial rubber insulation. To provide the required cable strength and flexibility, a glass fiber overbraid generally is provided coaxially over the inner insulation layer and an outer layer of rubber insulation is extruded coaxially over it.
Such glass overbraids are expensive to make, difficult to handle, and time-consuming to include in a cable. Nonetheless, inclusion of such braids has normally been necessary to insure that the ignition cable has the requisite strength, useful life, and other proprities.